There were more than a few people, myself included, who privately thought Dave Brailsford, Team Sky's director, may have been a bit rash in 2009 when he set a target of delivering a British winner of the Tour de France within five years. Maybe by 2020, I thought. Another part of me hardly expected to see a UK cyclist on the top step of the podium on the Champs Elysées in my lifetime.

Brailsford's ambition was, as the Tour classifies its highest climbs, hors catégorie. The achievement of the Londoner Bradley Wiggins in winning this 99th edition of the race, founded in 1903, is more than merely historic; it is monumental. A number of Britons have worn the leader's yellow jersey for a day or a handful of stages: Sean Yates, Chris Boardman, David Millar and Tommy Simpson. But none came close to winning the blue riband event of world cycling; none closer, at any rate, than Bradley Wiggins's own fourth place in 2009.

By winning outright the 2012 Tour de France, Wiggins joins a pantheon of greats. For anyone as steeped as he is in the history of cycle racing and the Tour, to be bracketed in the same league as riders of the past such as Louison Bobet, Fausto Coppi, Jacques Anquetil, Eddy Merckx and Bernard Hinault is a lifetime achievement in itself. In its more than 100-year history, the Tour has belonged almost exclusively to the countries of continental Europe; Lance Armstrong's seven straight wins (if they stand, after Usada's doping charges are heard) were an aberration.

For a Briton to win the Tour is as seismic, in its way, as it was for the first American to do so, in 1986. Like the US, Britain has been until now an outsider in the "world" of professional cycling – and Bradley Wiggins is our Greg LeMond.

He may lack the chutzpah, charisma and craziness of LeMond, but in his bloody-minded dedication and grit, Wiggins has shown himself a truly British champion. Having raised expectations in 2009, a combination of bad luck and disappointing performances relegated him to 24th place in 2010; in 2011, he crashed out with a broken collarbone. His victory in 2012 is the final realisation of great potential transformed by an unimaginable amount of hard work – not just his own training regime, but the collective effort of his team-mates (most notably, second-placed Chris Froome) and the ultra-rigorous, appliance-of-science approach of Brailsford's Team Sky.

A large part of the story is the physical and psychological transformation of Wiggins himself. There was never any doubting the raw talent of the self-styled mod from off the Edgware Road, but he had formerly seemed a Tour contender only for solo stages raced against the clock – the individual time trial and prologue. Wiggins Mk1 was a track specialist, a pursuiter who had cornered the 4km time trial event in the velodrome and won a fistful of Olympic medals in 2000, 2004 and 2008. On the road, his type – a lanky physique with long levers and a big engine, capable of sustained high aerobic output – is known as a rouleur.

Rouleurs can win single stages or one-day races by escaping and outrunning the pack. But a Tour winner has to be the perfect all-rounder: able to hang with the specialist climbers at 2,000m over the Col du Tourmalet, yet powerful enough to survive the cobbles of the French-Belgian borders and crosswinds of Les Landes. The rouleur is equipped for the former, but in the Alps and Pyrenees, where the Tour is decided, gravity is against him.

The trick of creating Wiggins 2.0 was to change the arithmetic: a rule of thumb says that a grand tour winner needs to be able to produce at least seven watts per kilo at peak aerobic output (to put that in perspective, a handy amateur racer might manage four watts/kg). For 2009, Wiggins shed 6kg (about a stone) off a frame where it was not obvious how such savings might be made. Maintaining "negative energy balance" is neither easy nor fun when your body is craving calories to compensate for the rigours of racing multiple back-to-back 200km-plus stages. If the Wiggins we see in press conferences now seems a little dour and phlegmatic, this was the price: he could no longer be the bloke who liked a few beers and would go on the lash for weeks after winning at the Olympics.

The leader of a team in the Tour de France has to be serious: a budget of millions is riding on his efforts, and he must show himself worthy of the sacrifices every one of his team-mates is expected to make. It was a telling vignette to see Mark Cavendish filling his world champion's rainbow jersey with water bottles from a Team Sky car to re-supply his team-mates in this year's race. Brad is answerable for that, and he knows it.

To some, Team Sky's ultimate domination of the 2012 Tour may have looked a little processional. That grossly underestimates Wiggins's and Sky's achievement in defending and extending his lead. The tactics are always the same, whoever you are, whatever the team, and in 2012 Wiggins and Sky were simply the best in world cycling's biggest event. Yet I also relished Wiggins's outburst against the "fucking wankers" among the Twitterati and press pack who had called into question the credibility of his performances. Wiggins's choice of Anglo-Saxon terms may have made Sky's press pack wince, but we needed to see that this coronation of a new champion was not a bloodless coup.

And Wiggins has a point. The 20 years between LeMond's last win and Wiggins's first were the dark era of EPO and blood-doping – low, dishonest decades that came close to wrecking the entire edifice of professional cycling and the Tour's prestige. We many burned fans are entitled to suspicion and scepticism; we have been lied to so often. But for this fan, at least, Bradley Wiggins's victory was all the more sweetly significant precisely because I believe in it. Chapeau Wiggo!